This is a picture of the battery case and charging electronics after I unsoldered the original li-ion cells.
Here I have two Li-Ion cells ready to solder together into a parallel pack. The technique that I found to work best was to insert a coil of small electronic solder between the tab and the bottom of the next battery, making sure that the solder never overlapped, so that their was always only one thickness of solder thick at any particular place. Then, I'd hold down the end of the tab with a screwdriver (to make sure it didn't bounce back up while the solder was still hot) and heat the tab with heavy downward pressure from a heavy duity (stained glass) soldering iron for a few seconds. I'd press down until the solder visiblely melted (usually accompanied by a puff of resin smoke) and the tab settled down. Then I'd remove the iron while keeping pressure with the screwdriver.
Important safety note: At the factory, tabs are welded to li-ion cells very quickly. Li-Ion cells will catch fire explosively if they are overheated. It is very important that you do not leave a soldering iron on the cells long enough to raise their internal temperatures to dangerous levels. Heat the tab, melt the solder, and then remove the iron.
You will note that I used one set of tabs to attach the two cells, and the other set of tabs was positioned 90 degrees off axis, to be used to connect to other packs of cells. Note that I'd use tape to hold the cells closely together while soldering them, but would remove the tape later to make them fit into the battery holder.
Here is my first pack, soldered to the charging electronics. Note that I have temporarily covered the exposed positive ends of these cells with clear plastic tape. This tape insulation is very important! It keeps this pack of cells from accidentally shorting through the pack of cells that I will add next. The process involves laying the cells on top of each other while soldering, and it is very dangerous to short out li-ion cells. (All of the charging electronics and fuses in the battery are designed just to keep that from happening.) Note that other things on your workbench can short out li-ion cells. For example, a coil of solder conducts electricity very well, at least until it melts. So do screwdrivers and pliers, and they are less likely to melt. Li-Ion cells are usually stored and shipped 40% full to prolong their life, and the ones I had certainly did spark a few times. A small spark here or there won't hurt anything, but if you short a cell for longer than a moment, it will begin to overheat and you could get into a runaway situation where it eventually catches fire explosively. Don't do that!
Once I've safely insulated the ends of these cells, I add the 2nd pack and solder them together.
After the tabs are soldered together, you can unfold the 2nd pack and lay it down flat.
When soldering existing metal tabs from the charging electronics to the cells, I found it best to coat the tabs with solder first, and then attach them to the cells. Below you can see a pre-existing tab that I pre-soldered before attempting to attach it to the back of the cells.
Note that the first and second pack have a good space between them (by design) in the battery holder, which leaves plenty of room for the solder tabs to be folded between the two packs of cells. However, the second and third packs must be mounted much closer together. Because I did not have a custom manufactured set of solder tabs, I found it easier to just butt the batteries up against each other and join the solder tabs above the cells.
Now, I have all three packs connected in serial, and to the charging electronics. All that remains is to find some very sticky double-sided tape to affix everything to the interior of the battery case. I suggest you use carpet-tape (designed for tacking down carpet), which appears to be about as strong as the original tape I removed from the case when disassembling it.
Once the tape is in place, all that remains is to snap the two halves of the battery case together, being careful to get all of the tabs in the right slots. Everything snaps together with a satisfying "clicking" noise, and the battery is as good as new. If you do not remove the manufacturers sticker (as I did) and are careful to use a plastic tool and not leave scrape marks when prying the battery apart (as, once again, I did) the battery will look practically like new.
But how does our existing charging charging circuitry deal with the brand new li-ion cells?
37 Comments
Jay, thanks so much for the Info! I had never even thought of that!
I bought an old panasonic toughbook for my daughter from ebay, and of course, the battery was dead. cost of a replacment on ebay: about a hundred bucks. a quick google search for the cells found them at about 3.50 each. total cost for 9 cells plus shipping:$45.26
you just saved me at least 50 bucks!
Thanks again! -
Great stuff!
Thanks for mentioning explosive batteries. They really stink too.
Its pretty easy to injure the batteries even if you dont explode them with the soldering iron. (= less capacity)
Warning, from the voice of experience: in addition to taking care to not overheat cells while soldering, also take care to not physically damage or deform the cells such as dent, ding or put undue pressure on them when re-assembling. Any physical damage can lead to an internal short and if the battery has sufficient charge, it will overheat and leak, smoke and/or explode, in that sequence.
BEWARE !!! , not all notebook battery can be refill like this way , some new smart notebook battery got a flash chip inside , when u took off the battery the chip is automatic erase , so you never can recharge your battery , even you change the new cell inside, u only can refill some old nb battery like 5 or 6 year old notebook !
How to know if flash chip is present on battery?
BTW Very nice howto
Plesae could someone tell me where I can purchase these batteries from!?!? The ones that go inside the battery pack.
I bought the batteries (li-ion cells) from http://www.batteryspace.com (it’s listed on the first page of the post.) Others sell them too, if you do a search for “18650 li-ion” on froogle.com plenty of dealers come up.
I got IBM R32 LAPTOP please advise how to open the battery pack and replace with an OEM cells..? Do you have some pics
Much appreciated. Best regards
The R batteries should be very similar to the X batteries. I used a Cell Phone opening tool (Green plastic pry bar) to gradually crack open the battery at the seam and “un-snap” each of the clip in snaps that hold the two halfs together.
I followed your lead and rebuilt my A20m’s battery pack (original IBM # 02K6618). I bought my cells from batteryspace and got the 2600 mAh cells. Worked great! Now, about resetting that flash chip…my pack has an AS358D flash chip. I’ve spent a lot of time looking on the web for info on reflashing the chip, and have only found one thing: “Smart Battery Workshop,” a program that claims it can read and reflash the chip. Problem: another company bought the program’s creators, and now only rebuilds batteries for you. The program was apparently well copy-protected and I can’t find a hacked copy. If anyone can find a way to reset the flash chip, we’ll all be good-to-go.
For those of you not as technicly inclined as most on this forum, and who consider refilling your batteries as a cheaper means of getting your old laptop back in order, this comment is for you. Beware refill services like Batteryrefill.com or the like who promise a “quick turnaround.” If you are the type who needs your laptop for flexibility and needs it often, you are better off buying a new battery rather than wait the 2+ months some of these services take to work on your batter.
Thanks for the great tutorial!
Would you have any advice on how to pry the battery case apart?
Lutz:
I used some plastic tools made for prying cell phones apart. It takes a bit of technique to do it without damaging the plastic. I basically get one of the two tools in place, and then slide it along while using the other tool to keep pressure on the crack.
I used one very much like the following: http://www.apscell.com/prytoolb.html
Jay
I replaced the 6 Li-ion cells in the pack for my IBM T40. I get great prices and service from allbattery.com. I guess I need to reflash the chip in the pack. The batteries measure 3.6 volts, but they won’t charge in the laptop. It sees the battery pack and says it’s 1% charged, but won’t charge.
I thought doing this stuff to my X21 battery. The only problem is: I can’t even start because I’m unable to OPEN the battery case. It’s a tight seal. Did you find this in the X31 battery too?
Eddy:
Yes, the two halves are sealed together very well. I used some plastic “cell phone opening” tools to gradually pry the sides apart, working the crack along as I went.
Jay
>I have a curiosity question
> which I wonder if you have ever considered or heard of
> elsewhere: Substituting lower cost NiMH cells for the Li-
> Ion cells.
While NiMH cells can be used in a battery, you should NEVER replace LiIon cells with NiMH cells. The reason for this is that the charging electronics in the battery are designed for LiIon cells, which are able to receive a much faster charge than the NiMH cells. If you tried to charge NiMH cells with a LiIon charging circuit, they would likely burst, burn, or even explode! Now, if you were able to find a battery pack that was similar to your notebooks (perhaps for an earlier model notebook in the same series that used NiMH batteries, you could replace the (LiIon) charging circuit with the NiMH charging circuit, and then you could use NiNM batteries.
Hi Jay,
which OS and/or which tool do you use to check the capacity?
Greetings from Munich/Germany
Chris
I’m using Linux (with acpi enabled) to get the detailed battery information.
cat /proc/acpi/battery/BAT0/info
Jay
>Hi Jay,
>which OS and/or which tool do you use >to check the capacity?
I found a way to reset the full-charge capacity for Power Manager on WinXP. Follow instructions given by Jay, but perform a “battery gauge reset” between your full discharge/charge cycles.
An additional tip for this to work well is to fully discharge with all timers off, and then fully charge with the thinkpad switched off.
The results are:
- 1st reset: 8.76 to 12.73Wh
- 2nd reset: 12.73 to 13.33Wh (didn’t do something right????)
- 3rd reset: 13.33 to 18.62Wh
- 4th reset: 18.62 to 27.45Wh
- 5th reset: 27.45 to 37.23Wh
- 6th reset: 37.23 to 45.72Wh
- 7th reset: 45.72 to 52.99Wh??
Now my R51e runs for almost 4.5hrs before reaching 1% on “max battery life” settings! (I replaced the cells with 2600mAh!)
Can we do this with lithium polymer?
Robert:
Lithium Polymer cells are basically LiIon cells that are more flexible, so should work just fine for this type of application.
Jay, or anyone, do you know if there is a flash chip set in my Toshiba Satellite M45 S3553? thanks
Also tips for opening up the battery pack would be nice, thanks
hello! and do I can use the NiMH cells and just recharge it in outside recharger not in notebook?
QAD417: I do NOT recommend using NiMH batteries to replace Li-Ion cells. If you did, you could not use the built in laptop Li-Ion charging circuit. You would instead need to use a NiMH charger (either outside the notebook as you suggested, or somehow built into the battery pack). [Of course, if the original battery pack used NiMH cells, you could replace them with NiMH cells.]
My battery at the moment has 4 3.7v (totaling 14.8) cells in series. There is space for 8 cells (there is a large capacity model that uses the same battery case). Could I create 4 banks (in series) of 2 cells (in parallel), still giving 14.8v but doubling the capacity. Will the charging circuit be able to cope? Will the battery me more likely to overheat (I guess the current drawn from each cell will be less so it will be cooler)?
Nathan:
Technically, every cell should be controlled independently. (That is why your existing charging circuit should have a wire that goes to the connections between each cell to the next, so that it can control the charging current to each cell independently.)
However, as long as you stick with a matched set of cells, I expect that you should be 100% safe if you “doubled up” each cell (in parallel). To the charging circuit, it would look like each of it’s individual cells just got more capacity. You are also correct that the power draw from each cell would be halved so the temperature should be cooler. (I expect that your battery would also take twice as long to charge.)
You are indeed lucky to have a battery with extra empty space in it, what model/brand is your laptop?
Jay
Thanks for the quick reply? Now the battery is apart I can see there is only one wire to each pair of cells (actually to the connecter between the two). The laptop is an IPC Multimedia Desknote E (though I have seen it alternatively branded). The battery is an EM-G320L1 (I think made by Elitegroup Computing Systems).
How do you open the plastic case of the Compaq Presario R3000 laptop battery, a 14.8V 6600mAH?
Do I have to cut it open?
Are there any higher capacity cells?
Thanks
I did a restore of my X31 battery and have soldered everything up correctly (looking at your pictures and ones I took before removing old cells) and the battery wont charge.
Watching the temps under linux show they stay normal but the charge/discharge rate doesn’t change. I left it hooked up for 20 minutes and nothing changes…should I just leave it longer?
Adam: It took me about 5-8 charge/discharge cycles to get my new battery charged all the way up (or at least, reporting that it was charged all the way up.)
It could be that the firmware/chip in your original battery does not allow the cells to be “replaced”, but my suggestion is that you run your laptop all the way down every night (and then charge it all the way back up) for a week and see if anything improves.
Jay
Nathan, how did you open the EM-G320L1? There aren’t any screws and I don’t want to tear up the case by prying indiscriminately.
I just opened up my laptop Battery (for Averatec 2300). The computer wont turn on with the battery. I left it plugged to the ac adapter for at least 4 hours, still the battery charge is at 0%.
With the battery case opened up, I can see each battery is at 3.8V, totaling around 11.5V. I even measured voltage at the connector :11.5V. The cells are still good! I guess it’s the flash chip. What can I do?
Hi Jay,
My battery for my Sony Vaio is not charging anymore; so I decided to buy a new battery. The prices of the battery in Japan however is about $250.00, so I stated thinking about repairing the battery. Your explanation was clear and very helpful. Thanks very much. I am going to try and replace the cells. Wish me luck.
Thanks
Regards
Dev
Jay, I just replace 6 batteries in a Toshiba battery pack (quite a task when you have low quality soldering tools).
So far it is charging and has the power to boot up the laptop. Problem is… it is DRAINING LIKE CRAZY! I got 6x 2200mAH batteries and I believe the old ones were 1800ish maybe.
I’m about to do a 2nd full charge and see how it goes. Is this normal for the first few recharge cycles?
Quick update:
Still draining battery for the 1st time but at 6% it doesn’t seem to down anymore.
Duc Tien,
If by “Draining like crazy” you mean that after the first charge the battery level indicator goes down rapidly (during the first discharge), then yes, this matches what happened to me.
The best I can come up with is that the charge control circuit thinks that it is still using your old cells, so when it sees a lot of current leaving the cells it figures that they are rapidly getting close to their “zero” point, and makes the percentage of battery left indicator drop appropriately.
In my experience, my laptop would continue to run for quite a while after the battery indicator reached the zero percent mark. (as in, 20-60 minutes!).
After several (5-6) full charge/discharge cycles, the charging circuitry eventually learns that the new calls were “better” than the old cells. (In my case, the battery capacity “increased” by about 10% each charge/discharge cycle.)
Jay
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